wso2 wait loop doesn't work after restart

Question

I've developed a pooling logic in bpel process on the WSO2 BPS 3.0.0 connected to a Postgresql 9 DB. It looks like this:

<bpel:repeatUntil name="RepeatUntilIncidentCompleted">
<bpel:sequence name="CheckIncidentStatus">
    <bpel:wait name="Wait">
        <bpel:for expressionLanguage="urn:oasis:names:tc:wsbpel:2.0:sublang:xpath1.0"><![CDATA['PT1M']]></bpel:for>
    </bpel:wait>
    <!-- invoke a service, copy status to a vStatus variable -->
</bpel:sequence>
<bpel:condition expressionLanguage="urn:oasis:names:tc:wsbpel:2.0:sublang:xpath1.0"><![CDATA[$vStatus=36]]></bpel:condition>

I created a process instance and this loop worked fine. Later I restarted the WSO2 BPS server. In the moment of the restart the process instance was in the loop, but after restart the loop wasn't running anymore. The process is marked as active in the carbon console.

I've added the in-memory=false property in the deploy.xml but it didn't help.

I could have missed some configuration but there also can be a persistence problem with such a loop (probably in the Apache ODE).

Does anyone know a solution to this problem? Thx in advance.

Answer 1

I've discovered that:
1. All sleep operations that you put in a wso2 bpel process are represented in the ode_job table. The attribute ts contains the time of wake up.
2. After restart of the bps server all delayed sleep operations aren't continued (a sleep operation is delayed when wake up time < current time - offset ).
3. After restart of the bps server all non-delayed sleep operations that are continued properly.

Now let's say that:
- You have a bpel process instance that waits in a wait operation. The wake up time is X.
- You stop the bps server, and start it again after X.
Because of 2. the process instance won't continue after restart. This includes the loop I've described earlier.

My workaround to the problem:
Everytime the wso2 bps server is restarted I execute a sql script on the database that updates the wake up attribute of the sleep operations (the ts column in the ode_job table). The wake up times are set to some near future.

I don't know if you can change the 2. / 3. behaviour by configuration. I couldn't find any documentation about it. Some code analasis is needed here. To make things worse, wso2 uses it's own apache ode branch, so you can't just update the apache ode library.

I suspect that there can be two reasons for the behaviour described in 2.:
- delayed sleep operations are droped
- delayed sleep operations are executed right after restart, but the process definitions aren't loaded yet.